Chlorination process

ABSTRACT

SC13A1C14 reacts in solution to perchlorinate the nucleus of benzene, mono- or di-substituted perhaloalkyl benzenes and oligophenylenes. The perchlorinated compounds are chemical intermediates, monomers to heat-resistant polymers and extreme pressure lubricant additives.

United States Patent Dorrenbos 451 Aug. 8, 1972 [54] CHLORINATION PROCESS [72] Inventor: Harold E. Dorrenbos,

Mich.

[73] Assignee: The Dow Chemical C0mpany,Mid-

land, Mich.

[22] Filed: June 3, 1970 [2i] Appl. No.: 43,183

Related US. Application Data [63] Continuation-impart of Ser. No. 724,635, April 26, l968, abandoned' Midland,

I [52] US. Cl ..260/612 R, 260/613 R, 260/644 R,

[56] References Cited UNITED STATES PATENTS 3,271,465 9/1966 Krewer et a1. ..260/65l OTHER PUBLICATIONS Ballester et al., J.A.C.S. 82 pp. 4,254- 4,258, 1960 Groggins, Unit Processes in Organic Synthesis, (l952) pp. 224

Primary Examiner-Howard T. Mars Attorney-Griswold & Burdick, L. Wayne White and C. E. Rehberg ABSTRACT SCl;,AlCl reacts in solution to perchlorinate the nucleus of benzene, monoor di-substituted perhaloalkyl benzenes and oligophenylenes. The perchlorinated compounds are chemical intermediates, monomers to heat-resistant polymers and extreme pressure lubricant additives.

11 Claims, No Drawings CHLORINATION PROCESS CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of my copending application, Ser. No. 724,635, filed Apr. 26, 1968 and now abandoned.

BACKGROUND OF THE INVENTION The invention herein described was made in the course of or under a contract with the Department of the Air Force.

Perchlorination of alkaromatic compounds is difficult because most reaction conditions for chlorination are sufficient to result in chlorinolysis, i.e. replacement of alkyl groups by chlorine.

A method of perchlorination is taught by M. Ballester, et al., J. Am. Chem. Soc., 82 4254 (1960), wherein a solution of S Cl AlCl and SO Cl are reacted with perhaloalkyl-substituted benzenes. This method is industrially unsatisfactory because of the physical properties of sulfuryl chloride, SO Cl and the necessarily large ratio of SO Cl to perchlorinated product obtained.

The perchlorinated alkaromatic compounds have utility as monomers to heat-resistant polymers as taught by (a) M. Ballester, et al., J. Am. Chem. Soc., 88, 957 (1966) and (b) US. Pat. No. 3,360,574 and also have utility as extreme pressure lubricant additives when added to lubricating oils, such as mineral oil, in 1-5 percent concentrations.

SUMMARY OF THE INVENTION It has now been discovered that SCl AlCl in solution, per chlorinates the nucleus of compounds of the formulae R1 R1 I and I Ra

, wherein R R R and R are each independently hydrogen, halogen, perhaloalkyl of 13 carbon atoms,

wherein R is hydrogen, halogen or perhaloalkyl of l to 3 carbon atoms. Suitable such materials include benzene, trichloromethylbenzene, pbis(trichloromethyl)benzene, mbis( trichloromethyl)benzene, biphenyl, 4- trichloromethylbiphenyl, 4,4- bis( trichloromethyl)biphenyl, chlorobenzene, 1,4- dichlorobenzene, l ,3-dichlorobenzene, bromobenzene, l ,4-dibromobenzene, triphenylmethane, diphenylether and other like compounds.

SCl AlCl is a solid, very reactive with water and alcohols and therefore. is handled in substantially anhydrous conditions for best results, and is prepared according to the method taught by O. Ruff and H. Golla,

2 Zeit anorg. allgem. Chem, 138, 17 (1924) or as illustrated hereinafter.

The chlorination process may be run in any solvent so long as the solvent is liquid under the process conditions and is inert to the chlorinating agent SCl AlCl Suitable inert solvents, for example, are chlorinated (generally perchlorinated) or oxychlorinated derivatives of the elements in groups 4a, 5a, 6a, 4b, 5b and 6b in the Periodic Table of the Elements. Suitable solvents, therefore, include perchlorinated aliphatic hydrocarbons, such as CCl Cl C CCl Cl C- C(Cl) CCl bis(trichloromethyl) ether, phosgene, and the like, SiCl Si OCl ,GeCl ,SnC1 PCl POCl P O Cl AsCl SbCl- SbCl SCl SOCI SO Cl SeCl SeOCl TiCl.,, VCl VOCl CrO Cl and the like. Preferred solvents are perchlorinated aliphatic hydrocarbons or the perchlorinated or oxychlorinated derivatives of phosphorus or sulfur. The most preferred solvents are CCl SOCI or SO Cl This preference is based on (1) the increased solubility of SCl AlCl in SOC1 as compared to SO Cl and CCL, (2) the relative ease of handling and (3) the economics of using CCl The concentration of SCl AlCl in solution may be adjusted to convenience but a highly concentrated solution is preferred. This solution may be prepared by (1) mixing SCl- AlCl with the solvent or 2) by reacting SCl with C1 and AlCl to yield SCl AlCl in situ. The latter preparation may be in a solvent or neat.

The mole ratio of reactants may be varied between 0.2-1 .4 moles of SCl AlCl, per atom of hydrogen to be replaced. If one uses less than a 1:1 ratio of reactants, the same degree of chlorination is obtained but at a lower rate. It is preferred to have an additional quantity of C1 present in the mixture, especially when less than a 1:1 ratio of reactant is used. One postulates that the C1 reacts with a species such as SCl AlCl.( to regenerate the chlorinating agent SCl AlCl in situ.

The reaction temperature is suitably from 50l 10 C. and preferably from 90 C. This preference is based on (1) kinetic data and (2) the fact that increasing amounts of decomposition are observed at temperatures above C.

The pressure used depends on the solvent and is conveniently atmospheric with SO Cl and autogenous with SOCl and CCl The preferred pressure is autogenous and includes the partial pressure of C1 GENERAL PROCEDURE Mix the material to be chlorinated with SCl AlCl in solution. Adjust the reaction temperature to about 50 "ll0 C. with stirring and maintain the reaction with water and filtering the aqueous mixture to obtain the residual product.

SPECIFIC EMBODIMENT The following examples are used to further illustrate the invention.

PREPARATION OF SCl AlCl.{

To 8.36 g. (0.081 mole) of SCl in one leg of an H- shaped glass container was added 5.77 g. (0.081 mole) of liquid C1 After mixing the two reactants at 80 C., 5

10.87 g. (0.081 mole) of anhydrous AlCl was added under a N blanket. The mixture was shaken and stored overnight at 80 C. The yellow-orange crystals which formed were extracted with distilled SO Cl to leave light yellow to white crystals of SClfAlCL, which decomposed at 120 C.

EXAMPLE 1 Preparation of perchloro-p-xylene Into a dry, heavy-walled 300 ml. glass tube was charged 5.35 g. (0.052 mole) of SCl The tube was placed in a bath at 78 C. and 32 g. (0.45 mole) of chlorine gas was condensed onto the SCI The mixture was stirred magnetically for 5 minutes. Then 6.73 g. (0.055 mole) of anhydrous AlCl was added to the stirred mixture. Stirring was continued for minutes. A total of 20.0 g. (0.064 mole) of 1,4- bis( trichloromethyl) benzene was added to the mixture along with 100 ml. of SOCl The tube was sealed off under a N blanket and the contents allowed to warm to room temperature. The tube was placed in an iron pipe and immersed in an oil bath at 80 C. for 24 hours. The

tube was then cooled and opened, and the SOCl was removed under vacuum. The solid residue remaining was washed with water. The resulting yellow crystals were dried and recrystallized from methylene chloride and petroleum ether. A total of 21.8 g. (76 percent of the theoretical yield) of decachloro-p-xylene was obtained. The remaining white product was octachloro-pxylene.

EXAMPLE 2 Preparation of Perchloro-p-bitolyl Using as the hydrocarbon substrate and following substantially the procedure of Example 1, 74 percent of the theoretical yield of perchloro-p-bitolyl was obtained.

EXAMPLE 3 Preparation of Perchloro-triphenylmethane as the hydrogen substrate and followingvsubstantially the procedure of Example 1, 51.3 percent of the theoretical yield of percl'iloro-triphenylmethane was obtained.

EXAMPLE 4 Preparation of Perchloro-p-bitolyl Into a 300 ml. glass tube was placed 15.0 g. of the anhydrous complex, SClfAlCh'. To this was added g. of liquid chlorine, 20.0 g. of 4,4- bis(trichloromethyl)diphenyl, and ml. of thionyl chloride. The tube was sealed, placed in an oil bath at 78 C. and stirred for 88 hours under autogenous pressure. At the end of this time the cooled tube was opened, the solvent removed under reduced pressure, and the residue treated with water and filtered. The dried residue yielded 25.7 g. (67 percent of the theoretical yield) of crystalline product when recrystallized from methyl isobutyl ketone.

EXAMPLE 5 Preparation of Decachloroxylene Using 15 g. of the complex, SCl AlCl.(, and 10 g. of l,4-bis(trichloromethyl)benzene in 600 ml. of sulfuryl chloride (SO Cl the reaction mixture was refluxed for 24 hours at atmospheric pressure. The product was worked up in the usual way. A total of 74 percent of the theoretical amount of the decachloroxylene was obtained in this manner.

lclaim:

1. A process of perchlorinating the nucleus of aromatic compounds comprising reacting by contacting SCl AlCl with a compound of the formula R1 R1 I wherein R R R and R are each independently hydrogen, chloro, bromo, perhaloalkyl of l to 3 carbon atoms,

and wherein R is hydrogen, chloro, bromo or perhaloalkyl of 1 to 3 carbon atoms, at a temperature between 50l 10 C. and in a reaction solvent inert to the chlorinating agent SCl AlCl said solvent being a perchlorinated aliphatic hydrocarbon, a perchlorinated derivative of phosphorus, sulfur, silicon, germanium, tin, arsenic, antimony, selenium, titanium or vanadium or an oxychlorinated derivative of phosphorus, sulfur, silicon, selenium, vanadium or chromium.

2. The process defined in claim 1 wherein the reaction temperature is 7090 C.

3. The process defined in claim 2 wherein about 0.2-1.4 moles of SCI AICL, are used per atom of hydrogen to be replaced and wherein the reaction solvent is SO Cl SOCl or CCl.,.

4. The process defined in claim 1 wherein the reaction solvent is a perchlorinated aliphatic hydrocarbon; or a perchlorinated or oxychlorinated derivative of phosphorus or sulfur.

and R are each independently hydrogen, chloro,

CCl

wherein R is hydrogen, chloro or CCl 9. The process defined in claim 8 wherein R and R are each hydrogen.

10. The process defined in claim 9 wherein R is 7. The process defined in claim 1 wherein the reac- 10 hydrogen.

tion solvent is SO Cl SOCl or CCl 8. The process defined in claim 1 wherein R R R,

11. The process defined in claim 10 wherein R is hydrogen. 

2. The process defined in claim 1 wherein the reaction temPerature is 70*-90* C.
 3. The process defined in claim 2 wherein about 0.2-1.4 moles of SCl3AlCl4 are used per atom of hydrogen to be replaced and wherein the reaction solvent is SO2Cl2, SOCl2 or CCl4.
 4. The process defined in claim 1 wherein the reaction solvent is a perchlorinated aliphatic hydrocarbon; or a perchlorinated or oxychlorinated derivative of phosphorus or sulfur.
 5. The process defined in claim 1 wherein about 0.2-1.4 moles of SCl3AlCl4 are used per atom of hydrogen to be replaced.
 6. The process defined in claim 1 wherein the reaction solvent is CCl4, Cl2C=CCl2, Cl3C-C(Cl)=CCl2, bis(trichloromethyl)ether, phosgene, SiCl4, Si2OCl6, GeCl4, SnCl4, PCl3, POCl3, P2O3Cl4, AsCl3, SbCl3, SbCl5, SCl2, SOCl2, SO2Cl2, SeCl2, SeOCl2, TiCl4, VCl4, VOCl3, or CrO2Cl2.
 7. The process defined in claim 1 wherein the reaction solvent is SO2Cl2, SOCl2, or CCl4.
 8. The process defined in claim 1 wherein R1, R2, R3 and R4 are each independently hydrogen, chloro, - CCl3, wherein R is hydrogen, chloro or -CCl3.
 9. The process defined in claim 8 wherein R2 and R4 are each hydrogen.
 10. The process defined in claim 9 wherein R is hydrogen.
 11. The process defined in claim 10 wherein R3 is hydrogen. 